Current compensation techniques for low-voltage high-performance current mirror circuits

摘要

This paper presents two current mirror circuits for low-voltage applications. Unlike most current mirrors that use stacked transistors in the output branch to boost the output resistance, the proposed designs use current compensation techniques to achieve high output resistance. By avoiding stacked transistors in the output branch, the minimum output voltages of the proposed circuits are significantly lower compared to those of other current mirror circuits with comparable output resistance. Particularly, the first design emphasizes on reducing the minimum output voltage to an extremely low level of around 20 mV. The second design stresses minimizing implementation cost. Compared to a simple current mirror circuit, the second design requires only one additional transistor but boosts the output resistance by more than 10 times. Both circuit analysis and simulations are presented to examine the performance of the proposed designs.